\\[-1.8ex] Soil Heterogeneity & $-$0.053 & $-$0.044$^{**}$ & $-$0.043$^{*}$ & $-$0.042$^{*}$ & $-$0.052$^{**}$ & $-$0.059$^{***}$ \\ 
  & (0.037) & (0.022) & (0.022) & (0.022) & (0.023) & (0.022) \\ 
\\[-1.8ex] 
Observations & 134,233 & 134,233 & 134,233 & 134,233 & 134,233 & 133,533 \\ 
R$^{2}$ & 0.0002 & 0.195 & 0.196 & 0.196 & 0.196 & 0.196 \\ 
